The present invention relates to a fluid dispenser comprising a receptacle, a dispenser member such as a pump or a valve, and a fixing ring for fixing the dispenser member to the receptacle. Such dispensers are widely used in the fields of perfumes, of cosmetics, or indeed pharmaceuticals, for dispensing fluids by depressing a pusher manually using a finger.
The present invention is concerned more particularly with a type of receptacle that forms an opening defining an inside wall which forms a narrow opening section below which the wall is recessed at least locally outwards to form a recessed bottom opening section. The fixing ring comprises firstly body-receiving means for receiving the body of the dispenser member and secondly a fixing skirt serving to be engaged by force into said opening. The skirt has an outside wall defining a first zone that comes into place at the narrow opening section, and a second zone that comes into place at the recessed opening section, when the skirt is engaged fully in the opening. A dispenser including such a fixing ring is known from Document U.S. Pat. No. 3,937,366. In that document, the inside wall of the neck of the receptacle is provided with a peripheral groove in which a rib formed on the outside wall of the skirt is snap-fastened. The portion of the skirt that is situated immediately above the rib has a diameter smaller than the diameter of the rib, even when the skirt is not yet engaged in the neck of the receptacle. It can be said that the outside profile of the skirt is exactly complementary to the inside profile of the neck of the receptacle. Similarly, the shape of the groove in the inside wall of the neck is exactly complementary to the shape of the rib on the skirt. Thus, there is no clamping radial contact between the skirt and the inside wall of the neck, but rather merely snap-fastening of the rib in the groove in the neck. Leakproofing between the skirt and the neck is thus very difficult to achieve.
An object of the present invention is to remedy the drawbacks of the prior art by defining a fixing ring that achieves both secure fixing and excellent leakproofing.
To achieve this object, the present invention provides that, before the skirt is engaged in the opening, the first zone of the skirt has an outside diameter that is larger than the inside diameter of the narrow opening section. This is not so in Document U.S. Pat. No. 3,937,366, in which the first zone of the skirt has a diameter that is strictly equal to the diameter of the neck at the opening therein. Advantageously, the narrow opening section is substantially undeformable, and the first zone can be deformed over the narrow opening section. In this way, by choosing a skirt diameter that is larger than the diameter of the narrow opening section, the skirt is deformed by material creep, so that the narrow opening section bites into the outside wall of the skirt, thereby guaranteeing secure fixing and excellent leakproofing. The first zone radially deforming inwards generates powerful radial clamping against the narrow opening section of the opening.
According to another characteristic, the second zone has an outside diameter that is larger than the inside diameter of the narrow opening section and that is smaller than the maximum inside diameter of the recessed opening section. The second zone, which is forced radially inwards on passing through the narrow opening section, is then free to relax by radially expanding outwards at the recessed opening section. Since the second zone is not in contact with the inside wall of the neck at the recessed opening section, it is easier for material to creep from the first zone to the second zone due to the interference caused by the narrow opening section biting into the first zone.
According to another feature of the invention, the skirt is spaced apart from the body by an intermediate space. Thus, the skirt being deformed can in no way generate deformation of the body of the dispenser member.
Advantageously, the ring further comprises a peripheral flange which extends radially outwards from the top end of the skirt and which serves to come into abutment contact against the opening in the receptacle to limit the depth to which the skirt can be engaged in the opening.
Preferably, the flange serves as a thrust-transferring member for engaging the skirt into the opening.
According to another feature of the invention, the narrow opening section is connected downwards to the recessed opening section via a substantially frustoconical or flared transition section. Thus, after the skirt is engaged in the opening, the outside wall of the skirt co-operates with the narrow opening section and with the transition section to improve fixing and leakproofing.
In a variant, or in addition, the narrow opening section extends upwards via a substantially frustoconical or flared leading section. Thus, after the skirt is engaged in the opening, the outside wall of the skirt co-operates with the narrow opening section and with the leading section to improve fixing and leakproofing.
In a practical embodiment, prior to being engaged, the outside wall of the skirt is cylindrical and has a constant outside diameter at the first and second zones. Advantageously, the skirt has a bevelled free bottom end in order to facilitate inserting it into the opening in the receptacle.